io_uring_enter.2: document IORING_RECVSEND_POLL_FIRST
io_uring_enter.2: document IORING_RECVSEND_POLL_FIRST

Signed-off-by: Pavel Begunkov <8608d41fe50396a9dbd36e830be65ba791e26c05@gmail.com>
Link: https://lore.kernel.org/r/46c7ba19248dd732241651da54bdcdee5f988d20.1666357688.git.8608d41fe50396a9dbd36e830be65ba791e26c05@gmail.com
Signed-off-by: Jens Axboe <cd8c6775e60d6f67a6984377324e5290df3d5358@kernel.dk>

axboe/liburing,axboe/liburing,axboe/liburing